The problematique of anthropogenic disturbance on African landscapes is studied within the double framework of DPSIR (Drivers Pressures States Impact Response) and Pattern/Process Paradygm (Landscape ... [more ▼]

The problematique of anthropogenic disturbance on African landscapes is studied within the double framework of DPSIR (Drivers Pressures States Impact Response) and Pattern/Process Paradygm (Landscape Ecology). 20 landscae images from D.R. Congo, Ivory Coast and Benin were studied using indexes of spatial (compositional and configurational) heterogeneity and anthropogenic disturbance in order to highlight the relationship between spatial structure and disturbance intensity. The results show maximal heterogeneity at intermediate anthropogenic disturbances and fasten the triangular relationship between anthropogenic effect, biodiversity and spatial heterogeneity, that had been partially theoretised with the intermidiate disturbance and habitat heterogeneity hypotheses. [less ▲]

Sea-level change is an important consequence of anthropogenic climate change, as higher sea levels increase the frequency of sea-level extremes and the impact of coastal flooding and erosion on the ... [more ▼]

Sea-level change is an important consequence of anthropogenic climate change, as higher sea levels increase the frequency of sea-level extremes and the impact of coastal flooding and erosion on the coastal environment, infrastructure and coastal communities1, 2. Although individual attribution studies have been done for ocean thermal expansion3, 4 and glacier mass loss5, two of the largest contributors to twentieth-century sea-level rise, this has not been done for the other contributors or total global mean sea-level change (GMSLC). Here, we evaluate the influence of greenhouse gases (GHGs), anthropogenic aerosols, natural radiative forcings and internal climate variability on sea-level contributions of ocean thermal expansion, glaciers, ice-sheet surface mass balance and total GMSLC. For each contribution, dedicated models are forced with results from the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate model archive6. The sum of all included contributions explains 74 ± 22% (±2σ) of the observed GMSLC over the period 1900–2005. The natural radiative forcing makes essentially zero contribution over the twentieth century (2 ± 15% over the period 1900–2005), but combined with the response to past climatic variations explains 67 ± 23% of the observed rise before 1950 and only 9 ± 18% after 1970 (38 ± 12% over the period 1900–2005). In contrast, the anthropogenic forcing (primarily a balance between a positive sea-level contribution from GHGs and a partially offsetting component from anthropogenic aerosols) explains only 15 ± 55% of the observations before 1950, but increases to become the dominant contribution to sea-level rise after 1970 (69 ± 31%), reaching 72 ± 39% in 2000 (37 ± 38% over the period 1900–2005). [less ▲]

Alluvial deposits of numerous rivers in the Ardennes have been dated by using iron slag content and 14C. On the basis of these analyses, several periods of increased sediment deposition have been ... [more ▼]

Alluvial deposits of numerous rivers in the Ardennes have been dated by using iron slag content and 14C. On the basis of these analyses, several periods of increased sediment deposition have been identified. Before the first deforestations, rivers in this region developed multiple channels in alluvial forests (anabranching rivers), which are still distinguishable in the topography of many floodplains by means of LIDAR survey. Moreover, during this period, floodplains were not well-developed and probably very humid, which explains the presence of peat layers within the alluvial sequences. In the Amblève catchment, the first increased sedimentary deposition of the Holocene occurred during the Bronze Age, probably in relation to deforestation and first cropland agriculture in the area. Archaeological data indicate Roman occupation in parts of the catchment, and Roman Period colluvium has been found at one site. Several peat layers have been dated in the Lienne catchment to around 1000 BP and probably indicate very low anthropogenic pressure. From the 11th Century onwards, there was an increase in sedimentation, coinciding with a higher concentration of charcoal in alluvial deposits. In many catchments there is an important increase in the sedimentation at the end of the 14th century, which can be related to the development of numerous iron-working sites. Analyses of slag concentration produced in these sites allow us to reconstruct the evolution of the floodplain topography in relation to the periods of blast furnaces activity. Total sedimentation in the smaller valleys since the initiation of iron industries amounts 0.5 to 1.0 m, which is in most cases about 40% of the total sediment present in the floodplains and corresponds to a mean sedimentation rate ranging between 10 and 20 cm/century. Such values are explained by former agricultural practices and woodland clearance associated with the huge demand for charcoal by the iron industry. For instance, about 20 ha of forest were cleared for the yearly consumption of a refining forge or a blast furnace and more than three hundred iron factories existed in the Ardenne Massif between the 14th and the 19th century. [less ▲]

Lead pollution history over Northern Poland was reconstructed for the last ca. 1300 years using the elemental and Pb isotope geochemistry of a dated Polish peat bog. The data show that Polish Pb–Zn ores ... [more ▼]

Lead pollution history over Northern Poland was reconstructed for the last ca. 1300 years using the elemental and Pb isotope geochemistry of a dated Polish peat bog. The data show that Polish Pb–Zn ores and coal were the main sources of Pb, other heavy metals and S over Northern Poland up until the industrial revolution. After review of the potential mobility of each element, most of the historical interpretation was based on Pb and Pb isotopes, the other chemical elements (Zn, Cu, Ni, S) being considered secondary indicators of pollution. During the last century, leaded gasoline also contributed to anthropogenic Pb pollution over Poland. Coal and Pb–Zn ores, however, remained important sources of pollution in Eastern European countries during the last 50 years, as demonstrated by a high 206Pb/207Pb ratio (1.153)relative to that of Western Europe (ca. 1.10). The Pb data for the last century were also in good agreement with modelled Pb inventories over Poland and the Baltic region. [less ▲]

Anthropogenic disturbances impact the whole biosphere, at least indirectly, and are of major concern in various disciplines and policies. To tackle it, most studies, specific to their thematic, create ... [more ▼]

Anthropogenic disturbances impact the whole biosphere, at least indirectly, and are of major concern in various disciplines and policies. To tackle it, most studies, specific to their thematic, create their own reference framework without connection with related purposes in other disciplines. This results in a plethora of terms and concepts that in turn impedes addressing that issue on a comprehensive way as well as complementarity between studies. Here, we clarify and synthesize the most frequently employed terms to characterise human impact on the environment (anthropisation, naturalness, hemeroby, novel ecosystem, analogous ecosystem, climax, etc.), their synonyms, the nuances and relationships between each of them, as well as the concepts used to designate the responses given by humans to environmental disturbances (restoration, management, conservation). We go on reviewing the methods used to assess anthropogenic changes, exploring different branches of ecology and geography. The strengths and weaknesses of the existing approaches are then used as a basis to develop a new analytical framework: we propose an action-oriented type of naturalness, and we develop a general methodology to quantify landscape anthropisation. Our methodology combines object-oriented and gradient analyses. Moreover, it is based on the assessment of ecosystem disturbance, landscape configuration and dynamics as well as on easily acquired data sets. Our integrated approach of the concern could be at the basis of land planning, environmental restoration and management practices as well as policies. [less ▲]

Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pH and carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms - such as corals and some plankton - will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean - carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual' scenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously. [less ▲]

Anthropogenic debris (AD) contaminate oceans and affect marine organisms in several ways. Plastic production is constantly increasing and it is estimated that 10% of this production end in the seas. As a ... [more ▼]

Anthropogenic debris (AD) contaminate oceans and affect marine organisms in several ways. Plastic production is constantly increasing and it is estimated that 10% of this production end in the seas. As a consequence, plastic is considered as an emerging contaminant and ingestions by organisms are increasingly reported. Microdebris (< 5mm) are available for a high range of organisms, including planktivorous fish, such as the European anchovy (Engraulis encrasicolus). Planktivorous fish have a particular gill basket, with long and tight gill rakers, related to their diet. Upon these gill rakers, small structures called denticles are present. These gill rakers act as a net to trap organic particles and AD. The aim of our study was to correlate sizes of AD ingested with the mesh constituted by the gill rakers and associated structures. Fifteen stomach contents were analyzed by Raman spectroscopy and particles were measured. Five gill arches were observed with a scanning electron microscope. Cellulose fibers and microplastics were the most AD ingested. Comparing to other Clupeiformes (pilchard and Atlantic herring), anchovies have more denticles on each gill rakers (personal data). AD ingestion by fish is poorly studied and impacts of AD are not much understood. Clupeiformes play a major role in marine ecosystems and is the most consumed order by humans. As the branchial basket constitutes a food selective apparatus, more morphological studies dealing with AD ingestion on Clupeiformes are needed. [less ▲]

in Proceedings of In the Wake of Plastics, Venice, October 13-15, 2015 (2015, October)

Anthropogenic debris (AB) contaminate oceans and affect marine organisms in several ways. Plastic production is constantly increasing and it is estimated that 10% of this production end in the seas. As a ... [more ▼]

Anthropogenic debris (AB) contaminate oceans and affect marine organisms in several ways. Plastic production is constantly increasing and it is estimated that 10% of this production end in the seas. As a consequence, plastic is considered as an emerging contaminant and ingestions by organisms are increasingly reported. Microdebris (< 5mm) are available for a high range of organisms, including planktivorous fish, such as the European anchovy (Engraulis encrasicolus). Planktivorous fish have a particular gill basket, with long and tight gill rakers, related to their diet. Upon these gill rakers, small structures called denticles are present. These gill rakers act as a net to trap organic particles and AB. The aim of our study was to correlate sizes of AB ingested with the mesh constituted by the gill rakers and associated structures. Fifteen stomach contents were analyzed by Raman spectroscopy and particles were measured. Five gill arches were observed with a scanning electron microscope. Cellulose fibers and microplastics were the most AB ingested. Comparing to other Clupeiformes (pilchard and Atlantic herring), anchovies have more denticles on each gill rakers (personal data). AB ingestion by fish is poorly studied and impacts of AB are not much understood. Clupeiformes play a major role in marine ecosystems and is the most consumed order by humans. As the branchial basket constitutes a food selective apparatus, more morphological studies dealing with AB ingestion on Clupeiformes are needed. [less ▲]

A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to ... [more ▼]

A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to the ocean. So far, global carbon budget estimates have implicitly assumed that the transformation and lateral transport of carbon along this aquatic continuum has remained unchanged since pre-industrial times. A synthesis of published work reveals the magnitude of present-day lateral carbon fluxes from land to ocean, and the extent to which human activities have altered these fluxes. We show that anthropogenic perturbation may have increased the flux of carbon to inland waters by as much as 1.0 Pg C yr-1 since pre-industrial times, mainly owing to enhanced carbon export from soils. Most of this additional carbon input to upstream rivers is either emitted back to the atmosphere as carbon dioxide (~0.4 Pg C yr-1) or sequestered in sediments (~0.5 Pg C yr-1) along the continuum of freshwater bodies, estuaries and coastal waters, leaving only a perturbation carbon input of ~0.1 Pg C yr-1 to the open ocean. According to our analysis, terrestrial ecosystems store ~0.9 Pg C yr-1 at present, which is in agreement with results from forest inventories but significantly differs from the figure of 1.5 Pg C yr-1 previously estimated when ignoring changes in lateral carbon fluxes. We suggest that carbon fluxes along the land–ocean aquatic continuum need to be included in global carbon dioxide budgets. [less ▲]

in General education in a changing world : containing papers read before the Society at the second General Meeting Berlin 1965 (1967)

Prior to becoming a dynamic factor in civilisation, education appears first of all as a result of it. In order to understand an educational situation - which one must, before undertaking a comparison ... [more ▼]

Prior to becoming a dynamic factor in civilisation, education appears first of all as a result of it. In order to understand an educational situation - which one must, before undertaking a comparison, - it is necessary to study its origin and growth. By maintaining that education is only the reflection of society, and more especially of its economy, Durkheim is directly propounding the modern anthropological theory. The secondary role of education is examined from 4 angles - in time (recurring influences) in space, at the same point in time and space, the disparity between educational theory and practice. Cultural anthropology endows a study of comparative education with a certain spirit and method. These are characterised by two words: relativism and globalism. The two ways of absorbing culture are then dealt with, i.e., the technical (learning of the thought technique) and the normative (learning of the normative ways of behaviour) processes of learning. It is regrettable that too many comparative educationalists neglect the normative aspect since this exercises a determining influence. This explains the artificial "bloodless" character of so many studies. The last part of the article is devoted to a study of the three vast normaLive factors of the culture-education complex. 1. The human order, which is both spatial (horizontal and vertical) and temporal. 2. The process of development. Amidst the phenomena brought to light, the idea of intercontinental acculturation processes is particularly outstanding. The procedure of cultural crises is also pointed out. The author finally underlines the importance of the notion of modal personality. 3. The ideals. Regardless of axiological differences among cultures, the average man's conceptions of beauty, good and truth are formed less by himself than by the civilisation in which he lives. All the same, it would be merely a convenient simplification to maintain that a simple culture adopts a clearly defined, fixed order of values. In conclusion, the need for co-operation between anthropologists and educators becomes increasingly evident. It is true that comparative education is bound up with other disciplines, but anthropology occupies a privileged position because, without its contribution, comparative education will remain for ever at a descriptive, even enumerative, level and for this reason will never be classed as one of the humanistic sciences. [less ▲]